refactor(timeline): extract the method to fetch a latest thread reply as an item

Do the ~~~loco~~ code motion 🎶

crates/matrix-sdk-ui/src/timeline/controller/state_transaction.rs

@@ -16,9 +16,11 @@ use std::collections::{HashMap, HashSet};
 
 use eyeball_im::VectorDiff;
 use itertools::Itertools as _;
-use matrix_sdk::deserialized_responses::{TimelineEvent, TimelineEventKind, UnsignedEventLocation};
+use matrix_sdk::deserialized_responses::{
+    ThreadSummaryStatus, TimelineEvent, TimelineEventKind, UnsignedEventLocation,
+};
 use ruma::{
-    events::AnySyncTimelineEvent, push::Action, serde::Raw, MilliSecondsSinceUnixEpoch,
+    events::AnySyncTimelineEvent, push::Action, serde::Raw, EventId, MilliSecondsSinceUnixEpoch,
     OwnedEventId, OwnedTransactionId, OwnedUserId, UserId,
 };
 use tracing::{debug, instrument, warn};
@@ -544,6 +546,36 @@ impl<'a> TimelineStateTransaction<'a> {
         }
     }
 
+    // Attempt to load a thread's latest reply as an embedded timeline item, either
+    // using the event cache or the storage.
+    async fn fetch_latest_thread_reply(
+        &mut self,
+        event_id: &EventId,
+        room_data_provider: &impl RoomDataProvider,
+    ) -> Option<Box<EmbeddedEvent>> {
+        let event = room_data_provider
+            .load_event(event_id)
+            .await
+            .inspect_err(|err| {
+                warn!("Failed to load thread latest event: {err}");
+            })
+            .ok()?;
+
+        EmbeddedEvent::try_from_timeline_event(
+            event,
+            room_data_provider,
+            &self.items,
+            &mut self.meta,
+        )
+        .await
+        .inspect_err(|err| {
+            warn!("Failed to extract thread latest event into a timeline item content: {err}");
+        })
+        .ok()
+        .flatten()
+        .map(Box::new)
+    }
+
     /// Handle a remote event.
     ///
     /// Returns whether an item has been removed from the timeline.
@@ -557,39 +589,12 @@ impl<'a> TimelineStateTransaction<'a> {
     ) -> RemovedItem {
         let TimelineEvent { push_actions, kind, thread_summary } = event;
 
-        let thread_summary = if let Some(summary) = thread_summary.summary() {
-            let latest_reply_item = if let Some(event_id) = summary.latest_reply.as_ref() {
-                // Attempt to load the timeline event, either from the event cache or the
-                // storage.
-                let event = room_data_provider
-                    .load_event(event_id)
-                    .await
-                    .inspect_err(|err| {
-                        warn!("Failed to load thread latest event: {err}");
-                    })
-                    .ok();
-
-                if let Some(event) = event {
-                    EmbeddedEvent::try_from_timeline_event(
-                        event,
-                        room_data_provider,
-                        &self.items,
-                        &mut self.meta,
-                    )
-                    .await
-                    .inspect_err(|err| {
-                        warn!("Failed to extract thread event into a timeline item content: {err}");
-                    })
-                    .ok()
-                    .flatten()
-                    .map(Box::new)
-                } else {
-                    None
-                }
+        let thread_summary = if let ThreadSummaryStatus::Some(summary) = thread_summary {
+            let latest_reply_item = if let Some(latest_reply) = summary.latest_reply {
+                self.fetch_latest_thread_reply(&latest_reply, room_data_provider).await
             } else {
                 None
             };
-
             Some(ThreadSummary {
                 latest_event: TimelineDetails::from_initial_value(latest_reply_item),
                 num_replies: summary.num_replies,